Accuracy of blood pressure measurements transmitted through a telemedicine system in underserved populations.

In underserved populations, inadequate surveillance and treatment allows hypertension to persist until actual cardiovascular events occur. Thus, we developed an Internet-based telemedicine system to address the suboptimal control of hypertension and other modifiable risk factors. To minimize cost, the subjects used home monitors for blood pressure (BP) measurements and entered these values into the telemedicine system. We hypothesized that patients could accurately measure their BP and transmit these values via a telemedicine system. Inner city and rural subjects (N = 464; 42% African-American or Hispanic) with 10% or greater 10-year risk of cardiovascular disease and with treatable risk factors were randomized into two groups, control group (CG) and telemedicine group (TG). Each subject received a home sphygmomanometer with memory. The TG recorded and entered BP at least weekly. During office visits, the BP meters were downloaded and recorded BP compared to BP values transmitted via telemedicine. The telemedicine (T) BP values were similar to the meter recorded (R) values (T: systolic/diastolic BP 133.4 +/- 11.1/77.5 +/- 6.8 mm Hg, and R: systolic/diastolic BP 136.4 +/- 11.9.4/79.7 +/- 7.5 mm Hg). The percent error was <1% for both systolic (-0.02 +/- 0.04%) and diastolic (-0.03 +/- 0.04%) BP. Lastly, the telemedicine BP values were similar to the office (O) BP values for systolic and diastolic BP (T: systolic/diastolic BP 133.4 +/- 11.1/77.5 +/- 6.8 mm Hg, and O: systolic/diastolic BP 136.3 +/- 20.5/78.1 +/- 10.5 mm Hg). In underserved populations, this inexpensive approach of patients using a home monitor and entering these values into a telemedicine system provided accurate BP data.